Signal indicator lamp



FIG. 1 is a front elevation view of a signal indicator lamp showing our new design;

FIG. 2 is a right side elevation view thereof, a left side elevation view being a mirror image of the right side elevation view;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken lines (where present) in all figures illustrate portions of the signal indicator lamp that form no part of the claimed design. 

CLAIM The ornamental design for a signal indicator lamp, as shown and described. 